Device for varying electrical coupling



L. M. CLEMENT.

DEVICE FOR VARYING ELECTRICAL COUPLING. APPLICATION msn JUNE 2o, 1918.

. 1,353,145, PatentedSept. 21,1920.

F/q. /5 k lm /6 Il l 1111 nr\ UNITED STATES PATENT OFFICE.

LEWIS M. CLEMENT, 0IL NEWARK, NEW JERSEYAVSSIGNOR T0 WESTERN ELECTRIC COMPANY, INCORPORATED, 0F NEW YORK, N. Y., A CORPORATION 0F NEW YORK.

DEVICE FOR VARYING ELECTRICALA COUPLING.

specification of Lettersratent. Patented Sept. 21, A192th Application filed June 20, 1918. Serial No. 240,968.

To all 'whom t may concern:

Be it known`that I, LEWIS M. CLEMENT, a citizen of the United States, residing at Newark, in the county of Essex, State of New Jersey, have invented certain new and useful Improvements in Devices for Varv- .ing Electrical Coupling, of which the fl- Vof coupled electrical circuits or impedances without thereby affecting the coupling between other pairs thereof.

A further object is to provide variable inductive coupling means suitable for use in signaling stations where it is of importance that variations of coupling be accomplished i rapidly and precisely.

A more particular Objectis to provide a mounting for related primary, secondary and tertiary coils whereby the coupling between the primary and secondary can be conveniently varied without varying the coupling between the secondary and tertiary, and the coupling between the secondary and tertiary can be varied without varying the coupling between the primary and secondary.

In the particular embodiment herein described, the use of the invention is exemplilied in connection with a station for receiving electromagnetic waves and is illustrated in the accompanying drawings, wherein Figure 1 is a perspective View with some parts in section of primary, secondary and feed-back coils with the coils represented as standing upright; Fig. 2 is a View of the operating handles and indicating scales which are connected with the coils; and Fig. 8 is a circuit diagram of a receiving circuit of a type wherein this .invention may be conveniently applied.

Primary coil 1, secondary 2 and feed-back coil 3 are mounted in a suitable cabinet or other container 4. rlhe primary coil 1 is supported by the bracket 5. Each of the coils has its winding in two semi-cylindrical parts and so wound that it has a negligible external iield and, therefore, does not affect any surrounding electrical apparatus which may be affected by Stray elds. The magnetic lield of each coil will pass'through one of the semi-cylindrical portions 'in a longitudinal direction and return through the other semi-cylindrical portion. The descriptive term astatic has been applied to such coils, which, when placed in end to end relation, as illustrated, will have maXimum coupling when the transverse parts of the windings of the respective coils are in one relation, and will have minimum coupling when the transverse parts are in another relation. Other coils or apparatus may be placed so as to be adjacent to or surround coils of this type without being alfected thereby. The coil 2 is rigidly attached by the bracket 6 to the spindle 7 which has attached thereto an operating handle 9 and is mounted in the bearing 8. A pointer 11 indicates upon a scale 12 the relative position of the coil 2 with respect to the coil 1 and hence the `Yrelative amounts of coupling or mutual inductance between the two coils. A spring 13, mounted between Ithe bracket 6 and bearing 8, serves to frictionally hold the coil 2 in position after it has been properly placed. The coil 3 is mounted upon a spindle 14:, which turns within the spindle 7 and has attached thereto an operating handle 15. By means of the handle 15, the coupling between the coils 2 and 3 can be varied from a maximum to a minimum as indicated by a pointer 16 upon a scale 17. An abutment 18 is provided upon the spindle 14 and a spring 19 is mounted between the abutment 18 and the bracket 6 to hold the coil 3 in position with respect to the coil 2 unless it is forcibly turned by operating handle 15. The spring 18 is designed to produce considerably greater friction than the spring 19 so that when the handle 15 is moved to rotate the coil 3, the coil 2 will continue to remain stationary on account of its Jrictional engagement with the bearing 8. However, when the coil 2 is rotated by the handle 9 the coil 3 will be carried with it. The mutual inductance between coils 1 and 8 will at all times be negligible. The leads to the coil windings will be flexible or of any other suitable nature to allow suliicient rotation of the coils. While described in connection with a special type of coil the invention may obviously be applied not only to other types of inductance coils but also to other electrical devices.

`cated serially in a receiving conductor 2O and coil 2 being located in a circuit between the cathode 21 and grid 22 of a vacuum tube V. The coil 3 is connected in any suitable manner, for feeding back energy from the output circuit 23 to the coil 2 for causing signals to be efiiciently received in the receiver or other suitable indicating device 24 as is wellknown, in the art. A condenser 25, variable condenser 26 and plate battery 27are well known elements of such receiving circuits and hence need no further mention.

The term electrically coupled as used herein is intended to define any coupling of two electrical elements whereby the electrical condition of one is influenced by the presence of the other. The term inductive coupling is herein used to signify electrostatic coupling, e. g. that between condenser plates, as well as electromagnetic coupling.

rIhe novel features of the invention, one form of which has been described above -in detail, are set forth both broadly and specifically in the appended claims.

lNlcat is claimed is:

.1. In combination, three electrical impedances, the first impedance being electrically coupled with the second and the second being electrically coupled with the third, means for changing the coupling between the first and second and simultaneously keeping the coupling between the second and third substantially constant, and means for changing the coupling between the second and third and simultaneously keeping the coupling between the first and second substantially constant, one of said means including devices for vsimultaneously acting upon two of said impedances.

2. In combination, three inductive elements, the first having a mutual inductance with the second and the second having a mutual inductance with the third, means for changing the mutual inductance between the first and second and simultaneously keeping the mutual inductance between the second and third substantially constant, and means for changing the mutual inductance between the second and third and simultaneously .keeping the mutual inductance between the first and second substantially con: stant, one of said means including devices for simultaneously acting upon two of said elements.

3. In combination, three electrical elements so mounted that the first has an inductive effect upon the second and the second has an inductive effect upon the third, means for changing the inductive relationship between the first and second and simultaneously keeping the relationship of the second and third constant, and means Lasarte for changing the inductive relationship between the second and third and simultaneously keeping the relationship between the first and second constant, one of said means including devices for simultaneously acting upon two of said elements.

4. In combination, a mounting, three .electrical elements mounted thereon on one side thereof, the first and secondl of said elements being coupled, the second and third thereof also being coupled, means for varying the coupling between the first and second, and means for varying the coupling between the second and third, both of said means being located on the side of said mounting remote from said elements.

5. In combination, three cylindrical induction elements permanently coaxially mounted, the first having a mutual inductance with the second and the second a mutual inductance with the third, means for changing the mutual inductance between the first and second while keeping the mutual inductance between the second and third substantially constant, and means for changing the mutual inductance between the second and third while keeping the mutual inductance between. the first and sec ond substantially constant.

6. In combination, three substantially lcylindrical inductive elements permanently coaxially mounted, means for rotating the second relatively to the first while keeping the third in fixed relative relation to the second, and means for rotating the third relatively to the second while keeping the second fixed relatively to the first.

7 In combination, a series of impedance elements, each of said series being coupled to one or more other members of the series, and means for changing the coupling between any two coupled members while keeping the coupling between the other members of the series including one of said two members constant, said means including a common means for moving two of said elements simultaneously.

8. In combination, a series of inductances, each of said series having a mutual inductance between itself and such members of the series as are adjacent thereto, and means for changing the mutual inductance between any two adjacent members while keeping the mutual inductance between one of said two members and another member of the series constant, said means includingv operating means for acting upon at least two of said inductances simultaneously.

9. In combination, a fixed coil and two movable coils, each of said movable coils being mounted upon a spindle, said spindles being so related as to have coincident axes, means for turning each of said spindles, means for causing the first of said spindles to turn when the means for turning the sec- :essaies causing the spacial relationship of the sec-- ond and third to remain constant, means for varying the spacial relationship between the third and the second, and means for simuli taneously causing the spacial relationship between the second and first to remain constant.

11. In a signaling system, a ixed coil and two movable coils, means for moving the first ofsaid movable coils with respect to said fixed coil, frictional means for causing the second of said movable coils to simultaneously move with said first coil, other means formoving said second coil, and frictional means for preventing said first coil from moving when said second coil is being moved by said other means.

12. In combination, in a signaling system,

. an astatic primary coil, an astatic secondary coil and an astatic feed-back coil, means for varying the mutual inductance between said primary and secondary coils without affecting the mutual inductance between said secondary and feed-back coil, and means for varying the mutual inductance between said secondary and feed-back coils without varying the mutual inductance between said primary and secondary coils.

13. Means for use in a signaling system including, in combination, a rigidly supported coil, a first rotary coil and a second rotary coil, a spindle for rotating both of said rotary coils with respect to said fixed coil and indicating means for indicating the relative position of said iirst rotary coil with respect to said fixed coil, a second spindle concentric with said first mentioned spindle for rotating said second rotary coil with respect to said rst rotary coil, and a second indicating means for indicating the position of said second rotary coil with respect to said first rotary coil.

11i. rIhe method oit' adjusting the coupling of three electrical devices which comprises adjusting theA second relatively to the third and simultaneously and automatically causing the first and second to maintain a constant relation, then adjusting the iirst relatively to the second and simultaneously and automatically causing the second and third to maintain a. constant relation.

15. In combination, a primary, a secondary and a tertiary coil, the first and second of said coils having a mutual inductance, and the second and third said coils having a mutual inductance, circuits individual to said coils, and means for changing the value of each mutual inductance without varying the other.

16. A thermionic repeater having a plate circuit and a grid circuit, a coil individual to each of said circuits, a signaling circuit, a coil individual to said signaling circuit, said grid and plate circuit coils being coupled, said signaling circuit and grid circuit coils being coupled, and means for varying the coupling between each of said pairs of coils while automatically maintaining the coupling between the other pair constant.

17. A thermionic repeater having a plate circuit and a grid circuit, a signaling circuit associa-ted therewith, a coil individual to each of said circuits, two of said coils having a substantial maximum mutual inductance, one of said two coils and the third coil having a substantial maximum mutual inductance, and means for varying the mutual inductance between each of said pairs of coils while automatically maintaining the mutual inductance betweenthe other pair constant.

- 18. Means for use in radio systems comprising two electromagnetically related astatic coils, a third astatic coil electromagnetically related to one of said coils, and means to change the relation of either of said coils to its related coil without affecting the relation of the related coil to the third coil.

19. A high frequency transformer comprising a rotatably mounted coil, a spindle for rotating said coil, a second rotatably mounted coil and a spindle for rotating said coil, said spindles being concentrically mounted.

In witness whereof, I ,hereunto subscribe my name this 14th day of June, A. D. 1918.

LEWIS M. CLEMENT.

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